1. Field of the Invention
The invention relates to motor vehicles, more especially a commercial vehicle of the type designed for stop and go operation such as buses on city street traffic, a garbage collection truck or the like, which includes a drive arrangement for the rear axle, consisting of an internal combustion engine whose output is connected with a variable speed transmission, especially an automatic transmission, and with brake energy recovery means encompassing a hydraulic oil tank, a hydraulic suction pump connected therewith, a high pressure hydraulic accumulator, a low pressure hydraulic accumulator, at least one hydraulic energy transducer which is selectively operable as a motor or as a pump, as well as hydraulic and electrical control means for controlling the charging and discharging sequences of the high pressure hydraulic accumulator.
2. Discussion of the Prior Art
A vehicle of this type is known from the description thereof in the German periodical "o+p, Oelhydraulik+Pneumatic", 22 (1976), No. 4, pages 195 to 199. In that instance, the drive arrangement for the rear axle and the device for the hydrostatic brake energy recovery are combined into a common hydraulic system, whereby an auxiliary drive is interposed between the hydrostatic transducer and the variable speed transmission, such auxiliary drive train being permanently connected; meaning, not being switchable. However, besides having the advantage in that this overall arrangement is compact, this possesses the disadvantage that upon the failure of one of the components, both systems are either impaired in their function, or may even become completely inoperative.